Social Phobia is a highly prevalent, disabling, and chronic anxiety disorder associated with substantial vocational, social, and academic impairment in adults as well as children. It increases the risk of depression, substance abuse and financial dependence. Nevertheless, social phobia has received less attention than other anxiety disorders, and there are universally accepted treatments for this condition. However, specific psychosocial and psychopharmacological treatments have demonstrated efficacy. Cognitive Behavioral Group Therapy (CBGT), developed by Heimberg, has proven superior to control therapies, while the MAOI phenelzine, first studied by Liebowitz, has proven superior to placebo in several controlled trials. In a novel and highly successful collaboration that has become a model in the field, Heimberg and Liebowitz together compared phenelzine, CBGT, pill placebo, and a credible psychosocial control treatment, and found phenelzine and CBGT, superior on a variety of measures and of distinct clinical benefit. Phenelzine was faster active and more effective than CBGT on some measures, while CBGT was more durable following treatment discontinuation. While phenelzine and CBGT produced positive effects, a number of patients, especially among generalized social phobics, did not respond sufficiently. There was also significant relapse following phenelzine discontinuation. Therefore, there is still a need for treatments for social phobia that are more effective and more durable than these two treatments as typically administered. Importantly, the combination of an MAOI and CBGT has never been evaluated. For many reasons, the combination treatment may be more effective than either individual therapy, more durable than medication alone, and especially effective for patients with generalized social phobia. If so, combined phenelzine/CBGT treatment would be of distinct benefit to many patients whose clinical needs are currently not well met. To address the acute efficacy issues, Liebowitz and Heimberg were funded to compare CBGT, phenelzine, the combination of these two treatments, and pill placebo in a 12-week trial of social phobia, and this trial is now underway. Outcome is evaluated by blind independent assessor interviews, self-report questionnaires, and standardized behavioral tests. The contributions of subtype and treatment site to outcome are also being examined. To date, a substantial number of patients have been enrolled, and combined treatment does appear to be more efficacious than either phenelzine or CBGT administered individually. However, two years of additional findings are being requested to complete study enrollment. When completed, this study should substantially enhance our knowledge of effective treatments for social phobia.